1. Field of the Invention
The present invention relates to a coater/developer (coating and developing apparatus) and a coating/developing method (coating and developing method) that apply resist liquid onto a substrate such as a semiconductor wafer or an LCD substrate (glass substrate for a liquid crystal display) and develop the resist film after its exposure to light, and a storage medium.
2. Description of the Related Art
In a semiconductor device or LCD substrate manufacturing process, a resist pattern is formed on a substrate with a technique called photolithography. This technique is implemented by a series of processes that forms a liquid film on the surface of a substrate such as a semiconductor wafer (hereinafter referred to as “wafer”) by coating the surface with resist liquid and develops the resist film after exposing the resist film to light using a photomask, thereby obtaining a desired pattern.
In general, such processing is performed using a resist pattern forming apparatus having a coater/developer that applies and develops resist liquid and an exposure unit connected to the coater/developer. In order to further increase the processing speed of the coater/developer, Japanese Laid-Open Patent Application No. 2006-203075 proposes a configuration that increases the throughput of the coater/developer by increasing conveyance efficiency by reducing a workload on conveyance means by vertically arranging an area for storing modules before exposure and an area for storing modules after exposure relative to each other and providing each area with conveyance means.
According to this technique, for example, as shown in FIG. 1, a carrier block S1′, a processing block S2′, and an interface block S3′ are laterally connected in this order, and the processing block S2′ is formed by stacking development blocks B1′ and B2′ that perform development, a coating block B4′ that applies resist liquid, and anti-reflection film forming blocks B3′ and B5′ that form corresponding anti-reflection films before and after application of the resist liquid, respectively. In each of the blocks B1′ through B5′ of the processing block S2′, there are provided a liquid processing part for performing liquid processing such as development, application of resist liquid, or application of chemical liquid for forming an anti-reflection film; multiple shelf units in which processing units for performing pre-processing and post-processing of the liquid processing are arranged in multiple tiers; and a corresponding one of conveyance means A1′ through A5′ conveying a wafer W between the liquid processing part and each part of the shelf units. Further, there are also provided dedicated transfer arms that transfer the wafer W among the blocks B1′ through B5′.
By conveying the wafer W to the processing block S2′ with a transfer arm C provided in the carrier block S1′ and conveying the wafer W to predetermined processing units using conveyance means A1′ through A5′ and the transfer arms, the workloads on the transfer arm C′, conveyance means A1′ through A5′, and the transfer arms are reduced so as to improve the throughput of the entire apparatus.
With such an apparatus, it is possible to ensure, for example, a throughput of approximately 180 wafers per hour. However, there is a market demand for apparatuses that further increase throughput to approximately 200 to 250 wafers per hour, and studies have been made by the inventors of the present invention of development of apparatuses that ensure such high throughput.
In the above-described apparatus, the shelf units provided in each of the development blocks B1′ and B2′ include processing units such as a heating unit called a post-exposure baking module or the like that heats the wafer W after exposure, a cooling unit for adjusting the wafer W to a predetermined temperature after processing in the heating unit, a heating unit called a post-baking module or the like that heats the wafer W after development so as to dry the wafer W, and a temperature adjusting unit for adjusting the wafer W to a predetermined temperature after processing in this heating unit.
For example, an apparatus that has a heating plate and a cooling plate and transfers the wafer W between the main arm A1′ or A2′ and the heating plate with the cooling plate, thereby performing heating and cooling in a single unit is employed as each of the heating units. In this case, the wafer W is transferred to and the wafer W after heating is transferred (received) from the heating units with the main arms A1′ and A2′ of the development units B1′ and B2′.
Compared with other blocks such as the resist liquid coating block B4′, the development blocks B1′ and B2′ have a large number of processing units performing processing on the wafer W before and after development as described above so as to have a heavy workload imposed on their main arms A1′ and A2′ that transfer/receive the wafer W to/from these processing units and the development unit. As a result, the processing rates of the development blocks B1′ and B2′ become rate-determining with respect to the other blocks B3′ through B5′, which is considered to be a cause of a decrease in the throughput of the entire apparatus. Therefore, studies have been made by the inventors of the present invention for achieving high throughput of the entire apparatus by improving the throughput of the development blocks B1′ and B2′.